Metallic materials are used in numerous applications where rigidity and high mechanical strength are required. For applications in which low density, lightweight metallic materials are desirable, aluminum and titanium metallic materials are generally suitable. Aluminum and titanium can be fusion welded to materials having compatible properties to provide a reliable and hermetic seal. For many applications, titanium exhibits superior properties and is a material of choice. Titanium, however, has relatively low thermal conductivity. For applications such as housings for electronic or electrical devices, where dissipation of heat from inside a three-dimensional structure or across a surface is necessary or desirable, titanium has generally not been considered as a consequence of its thermal conductivity properties.
Metal matrix composite materials, which incorporate a non-metallic reinforcing material dispersed within a metal matrix or host material, generally have desirable properties for many applications, including a low density, low CTE, high thermal conductivity and good mechanical strength. These properties may be manipulated somewhat by selecting the metal matrix material and the form, proportion and composition of the reinforcing material. Metal matrix materials comprising aluminum or aluminum alloy matrices incorporating silicon carbide reinforcing material have desirable properties for many applications.
Metal matrix composite materials have several practical disadvantages. Such materials generally cannot be machined and are provided in a three-dimensional configuration using a casting process. The use of casting techniques limits the tolerances and versatility of the three dimensional configurations available and increases the cost of producing three dimensional shapes. Metal matrix materials generally cannot be laser welded as a consequence of differences in energy absorption rates between the metal matrix material and the non-metal reinforcing material. Such materials must be joined to other components or structural materials using soldering or welding techniques, which are generally less reliable than fusion welding techniques.
It would therefore be desirable to provide a composite material in which the desirable properties of titanium and similar metals may be used advantageously, while additional desirable properties, such as high thermal conductivity, are also provided.